Rescheduled issues from 11.6 to 11.8 (8)

The following were rescheduled because the previous milestone was already closed:

• Loading Bars in Userpopover stay if location is null ~"Manage", ~"P3", ~"Pick into 11.6", ~"S4", ~"bug", frontend, regression:11.6
• Do not allow extending enums for CI ~"Accepting merge requests", Delivery, ~"backstage"
• WIP: Test plan for "Send one email notification for one published code review" ~"Create", Quality, ~"test plan"
• Remove projects/approvers#destroy action ~"Create", approvals, backend, ~"backstage", ~"technical debt"
• Batch Comments: deal with pending comments on lines that get changed before publishing review ~"Accepting merge requests", ~"Create", UX, UX debt, ~"code review", ~"devops:create", frontend, merge requests
• Improve performance of blob template dropdown rendering ~"Accepting merge requests", ~"Create", ~"P3", backend, ~"devops:create", ~"performance", ~"technical debt"
• New branch push is incorrectly failing size file gitlab hook ~"Accepting merge requests", ~"Create", ~"Gitaly", ~"P2", ~"S3", backend, ~"bug", ~"devops:create", needs investigation, repository
• Add pull mirroring integration tests ~"Accepting merge requests", ~"Create", QA, Quality, ~"mirror", test

Please reschedule accordingly if they're wrong.